maint: Clean up BIST tests so they don't produce warnings. * data.cc (Fhorzcat): Temporarily disable "num-to-str" warning for BIST tests. * luinc.cc (__luinc__): Move BIST tests to luinc.m. * luinc.m: Add BIST tests for luinc. * regexp.cc (Fregexp): Temporarily disable "regexp-lookbehind-limit" for BIST tests. * sqrtm.cc (Fsqrtm): Temporarily disable "sqrtm:SingularMatrix" for BIST tests. * __eigs__.cc, __init_fltk__.cc, __init_gnuplot__.cc: Add 'assert (1)' BIST test to mark internal functions as tested. * ov-range.cc (Fallow_noninteger_range_as_index: Temporarily disable "deprecated-syntax" for BIST tests. * quadv.m: Temporarily disable "divide-by-zero" warning for BIST tests. * imfinfo.m: Temporarily disable "GraphicsMagic-Quantum-Depth" for BIST tests.

To cite GNU Octave in publications use:

  John W. Eaton, David Bateman, Søren Hauberg, Rik Wehbring (2015).
  GNU Octave version 4.0.0 manual: a high-level interactive language for
  numerical computations.
  URL http://www.gnu.org/software/octave/doc/interpreter/

A BibTeX entry for LaTeX users is:

  @book{,
    author    = {John W. Eaton, David Bateman, S\oren Hauberg, and Rik Wehbring},
    title     = {{GNU Octave} version 4.0.0 manual: a high-level interactive language for numerical computations},
    year      = {2015},
    url       = {http://www.gnu.org/software/octave/doc/interpreter},
  }

We have invested a lot of time and effort in creating GNU Octave, please cite it
when using it.  See also `citation pkgname' for citing Octave packages.